JP5085649B2 - Silsesquioxane resin system containing basic additives with electron withdrawing groups - Google Patents

Description

  This patent application claims priority from US Provisional Patent Application No. 60 / 806,091, filed June 28, 2006, the disclosure of which is incorporated herein by reference.

The electronics industry is always under pressure to provide higher performance, smaller, faster and cheaper devices than the previous generation. In the semiconductor industry, the critical processing dimensions have been continuously miniaturized, and the required exposure wavelength has been changed from visible light (G-line, 436 nm) to ultraviolet (UV) (I-line, 365 nm), deep ultraviolet (DUV, 248 nm). , KrF), extreme ultraviolet rays (193 nm, ArF), 157 nm (F ₂ ), and even extreme ultraviolet rays (EUV, 13 nm). In recent years, 193 nm immersion lithography has been used as a technology that can be used in the 65 nm technology node and beyond. The chemically amplified photoresist preferably has all the strict conditions required for microlithography at a given wavelength (for example, transparency, chemical amplification ability, developer commonly used in the industry (for example, tetramethylammonium hydroxide (TMAH)). ), Plasma etching resistance, good adhesion to the substrate, high thermal and mechanical properties for processing).

  In order to withstand plasma (RIE) etching, it is necessary to maintain the resist at a specific film thickness (about 400 nm). Accordingly, the aspect ratio increases (> 5 or so) as the processing dimensions become finer. As a result, pattern collapse occurs during the pattern transfer process. This can be said to be a key problem in the case of performing finer processing (that is, 85 nm or more) using a single layer resist.

  In order to cope with the problem of pattern collapse, a multi-layer (ML) process (for example, a three-layer process) has been studied. In this multilayer process, a thin single-layer (SL) resist is coated on a thin hard mask. The main problem in the three-layer process is that it is difficult to provide a hard mask layer that has not only high etch resistance but also optical properties that match the upper and lower layers. Other compatibility issues exist as problems to be solved. Furthermore, it is expected that the number of processes is large and high-cost processing is required.

  Another type of multi-layer process is a bi-layer (BL) process. In this two-layer process, pattern collapse is prevented or minimized by using a thin upper image layer (about 150 nm) (usually a silicon-containing resist). The upper image layer is usually formed on a lower film such as a high energy absorbing organic layer (for example, an antireflection film (ARC)). Such a two-layer process is particularly attractive because it avoids many of the problems that can occur with single-layer and multi-layer processes and is a simple and cost-effective process.

  The silicon-containing two-layer resist can realize good etching selectivity in anisotropic etching processing, for example, reactive ion etching (RIE) using oxygen-containing plasma. Usually, when the silicon content (% by mass) in the silicon-containing resist is high, the etching resistance is also increased.

  However, there are many challenges to overcome in the development of silicon-containing resins useful for two-layer resist compositions for 193 nm or 157 nm photolithography. The first is that it is difficult for the polymer to contain silicon in a high proportion (ie> 15% by weight, necessary to impart high etch resistance). Second, most silsesquioxane-based resins have low thermal stability (ie low Tg), making it difficult to achieve high resolution, high sensitivity, and high process tolerance as a two-layer resist composition. This is the point. Third, outgassing of silicon-containing components during exposure at 193 nm is one of the major problems with silicon-containing polymers. Furthermore, many components in the resist composition (eg, basic quenchers and photoacid generators (PAGs)) can affect the silsesquioxane resin, thereby affecting storage stability.

  Since the critical dimension (CD) is miniaturized, pattern collapse frequently occurring in conventional single-layer resists reduces their etching resistance, which is a serious problem. Therefore, there is a need for the development of improved silicon-containing resins useful for two-layer resist compositions for 193 nm or 157 nm photolithography. Specifically, it has high etching resistance (high silicon content), and by incorporating all silicon into the polymer main chain, generation of outgas caused by silicon is minimized, and thermal stability is high. There is a need for the development of silicon-containing resins that have increased process latitude. There is also a need for a silicon-containing resist composition that provides high sensitivity and high resolution to widen the process window. Furthermore, there is a need for silicon-containing resist compositions that have improved stability and thus improved resist shelf life.

  Since hydrogen silsesquioxane (HSQ) has a unique structure and a high ratio of Si—H bonds, transparency at 193 nm and 157 nm is remarkably high. For example, HSQ (commercially available from Dow Corning under the trade name FOx (registered trademark)) is widely used as a spin-on type low-k dielectric material, and various properties (for example, thin film properties, thermal properties, etc.) required for good photoresists are used. Characteristic and mechanical properties). HSQ is also rapidly soluble in an alkaline aqueous solution (for example, in tetramethylammonium hydroxide (TMAH), which is a widely used developer), and the Si—H bond is rapidly changed to an Si—OH group. It is thought to be. However, it is very difficult, if not impossible, to directly incorporate acid-labile functional groups into the HSQ main chain to obtain HSQ useful as a photoresist.

WO 2005/007747 pamphlet (Patent Document 1, incorporated herein by reference) includes the following general formula (HSiO _3/2 ) _a (RSiO _3/2 ) _b
(Wherein R represents an acid dissociable group,
a is 0.2 to 0.9,
b is 0.1 to 0.8,
0.9 ≦ a + b ≦ 1.0. )
An HSQ-based resin represented by: These HSQ resins are suitable for use as a photoresist. However, since these resins do not exhibit long-term stability, their use is limited.

International Publication No. 2005/007747 Pamphlet

  The present invention relates to the provision of a novel silsesquioxane-based composition.

The composition is
(A) a silsesquioxane resin having an HSiO _3/2 unit and an RSiO _3/2 unit (wherein R represents an acid dissociable group);
(B) 7-diethylamino-4-methylcoumarin.

  7-diethylamino-4-methylcoumarin stabilizes the silsesquioxane resin, thereby improving storage stability. This composition can be used as a photoresist composition. In addition, the said silsesquioxane resin may be described in the international publication 2005/007747 pamphlet, for example.

The silsesquioxane resin of the present invention has HSiO _3/2 units and RSiO _3/2 units (wherein R represents an acid dissociable group). Such a resin has the following formula (HSiO _3/2 ) _a (RSiO _3/2 ) _b
(Wherein a is 0.2 to 0.9,
b is 0.1 to 0.8,
0.9 ≦ a + b ≦ 1.0. )
It may be represented by Alternatively, a is 0.4 to 0.8 and b is 0.2 to 0.6. Since the SiH ratio in the resin is high, the resist is considered to have high transparency to 193 nm and 157 nm light (low OD value) and high sensitivity to light. Moreover, since the Si ratio in the resin having a Si—O bond in the main chain is high (maximum 40 mass%), the resist containing the silsesquioxane resin of the present invention has high etching resistance and low outgas ( Or no outgassing).

Silsesquioxane resin has the following general formula (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c
(Wherein R, a, and b are as described above,
R ¹ represents a group selected from a hydrogen atom and a linear or branched C ₁ -C ₆ alkyl group;
c is 0.01 to 0.4, or 0.05 to 0.15,
0.9 ≦ a + b + c ≦ 1.0. )
It may be represented by The presence of the HSi (OR ¹ ) O _2/2 unit is considered to improve the adhesion of the resin to the substrate when the resin is used as a resist.

The present invention also provides the following general formula: (HSiO _3/2 ) _a (RSiO _3/2 ) _b (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d
Wherein R, R ¹ , a and b are as described above,
d is 0.05 to 0.45, or 0.1 to 0.25,
0.9 ≦ a + b + d ≦ 1.0,
x is 0-3. )
The present invention relates to the provision of a silsesquioxane resin represented by: The presence of Si (OR ¹ ) _x O _{(4-x) / 2} units enhances the heat resistance of the resin and increases Tg, thereby improving resist resolution, contrast, line edge roughness (LER), etc. Is done.

The invention also relates to the general formula (HSiO _3/2 ) _a (RSiO _3/2 ) _b (R ² SiO _3/2 ) _e
(Wherein R, a, and b are as described above,
R ² represents a property-modifying functional group,
e is 0.01 to 0.25, or 0.05 to 0.15,
0.9 ≦ a + b + e ≦ 1.0. ).
The present invention relates to the provision of a silsesquioxane resin represented by: The R ² group is used to modify properties (eg, adhesion and Tg).

The present invention also provides the following general formula: (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c (R ² SiO _3/2 ) _e
Wherein R, R ¹ , R ² , a, b, c, and e are as described above,
0.9 ≦ a + b + c + e ≦ 1.0. )
The present invention relates to the provision of a silsesquioxane resin represented by:

The present invention also provides the following general formula: (HSiO _3/2 ) _a (RSiO _3/2 ) _b (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d (R ² SiO _3/2 ) _e
Wherein R, R ¹ , R ² , a, b, d, e, and x are as described above,
0.9 ≦ a + b + d + e ≦ 1.0. )
The present invention relates to the provision of a silsesquioxane resin represented by:

The present invention also provides the following general formula: (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d
Wherein R, R ¹ , a, b, c, d, and x are as described above,
0.9 ≦ a + b + c + d ≦ 1.0. )
The present invention relates to the provision of a silsesquioxane resin represented by:

The present invention also provides the following general formula: (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d (R ² SiO _3/2 ) _e
Wherein R, R ¹ , R ² , a, b, c, d, e, and x are as described above,
0.9 ≦ a + b + c + d + e ≦ 1.0. )
The present invention relates to the provision of a silsesquioxane resin represented by:

  The silsesquioxane resin of the present invention is not only highly transparent at a short wavelength, but also has many required characteristics in a positive resist (for example, adhesion, heat resistance, chemical amplification ability, aqueous alkali dissolution after photodeprotection) Sex).

The silsesquioxane resin of the present invention has HSiO _3/2 units and RSiO _3/2 units (wherein R represents an acid dissociable group). “Acid-dissociable group” means a group in a molecule that can be dissociated by an acid, particularly a photogenerated acid (PGA). Acid dissociable groups are known in the prior art and are described, for example, in European Patent Application Publication No. 11442928 and US Patent Application Publication No. 2002/0090572. This is incorporated into the description. Specifically, the acid dissociable group can be represented by the following formula.

（式中、Ｒ³はそれぞれ独立に連結基を示し、
Ｒ⁴は第２の連結基を示し、
Ｌは炭素数１〜１０の直鎖状又は分岐鎖状のアルキレン基、炭素数２〜２０のフルオロアルキレン基、置換及び非置換のアリーレン基、置換及び非置換のシクロアルキレン基、並びに置換及び非置換のアルカリーレン基からなる群から選択される基を示し、
Ｒ⁵は水素原子、直鎖状若しくは分岐鎖状のアルキル基、又はフルオロアルキル基を示し、
Ｒ⁶はアルキル基又はフルオロアルキル基を示し、
Ｚは酸解離性基を示し、
ｆは０又は１であり、
ｇは０又は１であり、
ｈは０又は１である。）

(In the formula, each R ³ independently represents a linking group;
R ⁴ represents a second linking group,
L represents a linear or branched alkylene group having 1 to 10 carbon atoms, a fluoroalkylene group having 2 to 20 carbon atoms, a substituted and unsubstituted arylene group, a substituted and unsubstituted cycloalkylene group, and a substituted and non-substituted group. Represents a group selected from the group consisting of substituted alkali-lene groups;
R ⁵ represents a hydrogen atom, a linear or branched alkyl group, or a fluoroalkyl group,
R ⁶ represents an alkyl group or a fluoroalkyl group,
Z represents an acid dissociable group,
f is 0 or 1,
g is 0 or 1,
h is 0 or 1. )

Each R ³ is not limited, and examples thereof include an alkylene group (methylene group, ethylene group, etc.).

Examples of R ⁴ include, but are not limited to, linear or branched alkylene groups, cycloalkylene groups (such as norbornyl group and cyclohexylene group), fluoroalkylene groups, and aryl groups.

  Examples of L include, but are not limited to, substituted (for example, fluorinated) and unsubstituted methylene groups, ethylene groups, norbornene groups, cycloalkylene groups, and alkalilene groups.

Examples of R ⁵ include, but are not limited to, a hydrogen atom, a C ₁ -C ₆ alkyl group (methyl group, ethyl group, etc.), and a C ₁ -C ₆ fluoroalkyl group (trifluoromethyl group, 2,2,2). -Trifluoroethyl group, 3,3,3-trifluoromethyl group, etc.).

Examples of R ⁶ include, but are not limited to, C ₁ -C ₆ alkyl groups (methyl group, ethyl group, etc.) and C ₁ -C ₆ fluoroalkyl groups (trifluoromethyl group, 2,2,2-trifluoro). Ethyl group, 3,3,3-trifluoropropyl group, etc.).

Z includes, but is not limited to, for example, —OH, —COOH, an ester of formula —COOR ⁷ , a carbonate of formula —OCOOR ⁸ , and an ether of formula —OR ⁹ , wherein R ⁷ , R ⁸ , And R ⁹ are selected to be acid dissociable.

In the acid dissociable group —COOR ⁷ , R ⁷ is, for example, a tertiary alkyl group (eg, t-butyl group), a cyclic or alicyclic substituent having a tertiary bond point (generally C ₇ -C ₁₂ ) (Adamantyl group, norbornyl group, isobornyl group, 2-methyl-2-adamantyl group, 2-methyl-2-isobornyl group, 2-butyl-2-adamantyl group, 2-propyl-2-isobornyl group, 2-methyl -2-tetracyclododecenyl group, 2-methyl-2-dihydrodicyclopentadienyl-cyclohexyl group, 1-methylcyclopentyl group, 1-methylcyclohexyl group, etc.), or 2-trialkylsilylethyl group ( 2-trimethylsilylethyl group, 2-triethylsilylethyl group, etc.).

Examples of the acid dissociable carbonate group represented by the formula —OCOOR ⁸ include —Ot-butoxycarbonyl group (R ⁸ is t-butyl group). Examples of the acid dissociable ether group represented by the formula —OR ⁹ include a tetrahydropyranyl ether group (R ⁹ is a tetrahydropyranyl group) and a trialkylsilyl ether group (R ⁹ is a trialkylsilyl group (for example, a trimethylsilyl group). ).

  Z is typically an organic ester group that undergoes a cleavage reaction in the presence of a photogenerated acid to yield a carboxylic acid group.

  Acid dissociable groups (R) include, but are not limited to, for example, norbornane 1,1-dimethylethyl ester, isopropyl ester, 2-methyladamantyl ester, cyclohexyl ester, 2-hydroxy-3-pinanyl ester, and t -Butyl ester etc. are mentioned.

In addition to (HSiO _3/2 ) (RSiO _3/2 ) units, HSi (OR ¹ ) O _2/2 units, Si (OR ¹ ) _x O _{(4-x) / 2} units, or (R ² SiO ₃ units _{) / 2} ) units, or any combination of these units, may be added to the silsesquioxane resin to enhance the performance of the silsesquioxane resin. R ¹ in these units independently represents a group selected from a hydrogen atom and a C ₁ -C ₆ alkyl group. Examples of R ¹ include, but are not limited to, a methyl group, an ethyl group, a propyl group, a butyl group, and a t-butyl group. Typically, R ¹ is a hydrogen atom or a methyl group. R ² has the structure —R ²¹ R ²² , where R ²² is typically —OH, —COOH, or an alkali-soluble moiety, and R ²¹ is a substituted and / or unsubstituted C ₁ — C ₁₂ (linear, branched or cyclic) alkyl moiety. Examples of R ² include, but are not limited to, a bicyclo [2.2.1] hept-5-en-2-1,1,1-trifluoro-2-trifluoromethylpropan-2-ol group, 2- Trifluoromethylbicyclo [2.2.1] hept-5-en-2-ol group, 3,3,3-trifluoropropan-2-ol group, and 2-trifluoromethyl-3,3-difluoro- Bicyclo [2.2.1] hept-5-en-2-ol group is mentioned.

The silsesquioxane resin is typically 5 to 60 mol%, more typically 5 HSi (OR ¹ ) O _2/2 units, based on all units in the silsesquioxane resin. -45 mol%. The silsesquioxane resin is more typically 5-45 mol% of Si (OR ¹ ) _x O _{(4-x) / 2} units relative to all units in the silsesquioxane resin. May have 10-25 mol%. Furthermore, the silsesquioxane resin, for all units in the silsesquioxane resin may have (R ² SiO _3/2) units 0-25 mole%, alternatively 10 to 15 mole% Good.

Examples of silsesquioxane resins include, but are not limited to, • (HSiO _3/2 ) _a (RSiO _3/2 ) _b
(Wherein R represents a group selected from isopropyl ester, 2-methyladamantyl ester, cyclohexyl ester, 2-hydroxy-3-pinanyl ester, and t-butyl ester of norbornane;
a is 0.4 to 0.9,
b is 0.1 to 0.6. ),
(HSiO _3/2 ) _a (RSiO _3/2 ) _b (R ¹ OSiO _3/2 ) _c (SiO _4/2 ) _d
Wherein R is selected from isopropyl-, 2-methyladamantyl-, cyclohexyl-, 2-hydroxy-3-pinanyl-, and t-butyl-bicyclo [2.2.1] heptane-2-carboxylate. Group,
R ¹ represents a hydrogen atom,
a is 0.5 to 0.7,
b is 0.2 to 0.45,
c is 0.05 to 0.2,
d is 0.01 to 0.1. ),
(HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d (R ² SiO _{3 / 2} ) _e
Wherein R is a group selected from isopropyl-, 2-methyladamantyl-, cyclohexyl-, 2-hydroxy-3-pinanyl- and t-butyl-bicyclo [2.2.1] heptane-2-carboxylate. Indicate
R ¹ represents a hydrogen atom,
R ² is bicyclo [2.2.1] hept-5-ene-2-1,1,1-trifluoro-2-trifluoromethylpropan-2-ol, 2-trifluoromethylbicyclo [2.2. 1] Hept-5-en-2-ol, 3,3,3-trifluoropropan-2-ol, and 2-trifluoromethyl-3,3-difluoro-bicyclo [2.2.1] hept-5 -Represents a group selected from en-2-ol,
a is 0.4 to 0.6,
b is 0.2 to 0.45,
c is 0.05-0.20,
d is 0.01 to 0.15,
e is 0.01 to 0.25,
x is 0-3. )
Is mentioned.

Preparation of the silsesquioxane resin of the present invention,
(A) a hydrogen silsesquioxane resin represented by the following formula:
(HSiO _3/2 ) _m (HSi (OR ¹ ) O _2/2 ) _n (Si (OR ¹ ) _x O _{(4-x) / 2} ) _p
(In the formula, each R ¹ independently represents a group selected from a hydrogen atom and a C ₁ -C ₆ alkyl group;
x is 0-3,
m is 0.7 to 1.0, typically 0.8 to 0.9,
n is 0 to 0.4, typically 0.05 to 0.3,
p is 0 to 0.45,
0.9 ≦ m + n + p ≦ 1.0, typically m + n + p≈1.0. )
(B) reacting with an acidic dissociable group precursor,
(C) It is carried out by generating a silsesquioxane resin represented by the following general formula.
(HSiO _3/2 ) _m1 (RSiO _3/2 ) _m2 (HSi (OR ¹ ) O _2/2 ) _n (Si (OR ¹ ) _x O _{(4-x) / 2} ) _p
Wherein R ¹ , n, p, and x are as described above,
R represents an acid dissociable group,
m2 is 0.1 to 0.6, typically 0.2 to 0.4,
m1 + m2≈m. )

  Methods for preparing the hydrogen silsesquioxane resin (A) are known. One method includes a method of hydrolyzing trihalosilane (such as trichlorosilane) or trialkoxysilane (such as triethoxysilane). Methods for preparing hydrogen silsesquioxane resins are not limited, but include, for example, Collins et al. US Pat. No. 3,615,272, Bank et al. US Pat. No. 5,010,159, Frye et al. US Pat. Carpenter et al., U.S. Pat. No. 6,353,074, U.S. Patent Application No. 10/060558, filed Jan. 30, 2002, JP-A-59-1778749, JP-A-60-86017, And JP-A-63-107122.

  The hydrogen silsesquioxane resin is reacted with the acid dissociable group precursor (B). One method of reacting the hydrogen silsesquioxane resin with the acid dissociable group precursor is to perform a catalytic hydrosilylation reaction between the acid dissociable group precursor and the hydrogen silsesquioxane resin. Can be mentioned.

Examples of the acid dissociable group precursor include, but are not limited to, t-butyl ester of norbornene, t-butyl (2-trifluoromethyl) acrylate, bicyclo [2.2.1] hept-5-ene-2 -T-butylcarboxylate, cis-5-norbornene-2,3-dicarboxyl anhydride and the like. Typically, an appropriate amount of the above acid dissociable group precursor is added, and the ratio of RSiO _3/2 units to all units in the silsesquioxane resin is 5 to 60 mol%, or 15 to 35 mol%. And

Hydrosilylation catalysts are known and include, but are not limited to, platinum-containing compounds, nickel-containing compounds, and rhodium-containing compounds. Examples of platinum-containing compounds include H ₂ PtCl ₆ , di-μ-carbonyldi-π-cyclopentadienyldinickel, platinum-carbonyl complex, platinum-divinyltetramethyldisiloxane complex, platinum cyclovinylmethylsiloxane complex, And platinum acetylacetonate (acac). Examples of rhodium-containing compounds include Rh (acac) ₂ (CO) ₂ , and examples of nickel-containing compounds include Ni (acac) ₂ . Typically, the amount of hydrosilylation catalyst used is from 10 to 10,000 ppm, or from 100 to 1,000 ppm, based on the amount of reactants (ie, hydrogen silsesquioxane resin and acid dissociable group precursor). Amount.

  The reaction between the hydrogen silsesquioxane resin and the acid dissociable group precursor is typically carried out at room temperature and atmospheric pressure, but heat or pressure may be applied to accelerate the reaction.

  The reaction between the hydrogen silsesquioxane and the acid dissociable group precursor is typically carried out in the presence of a solvent. Examples of such solvents include, but are not limited to, alcohols (ethyl alcohol, isopropyl alcohol, etc.), aromatic hydrocarbons (benzene, toluene, etc.), alkanes (n-heptane, dodecane, nonane, etc.), ketones (methyl isobutyl ketone, etc.). ), Ester, glycol ether, siloxane (cyclic dimethylpolysiloxane, linear dimethylpolysiloxane (eg, hexamethyldisiloxane, octamethyltrisiloxane, and mixtures thereof)), 2-ethoxyethanol, propylene glycol monomethyl ether Examples include acetate (PGMEA), cyclohexanone, 1,2-diethoxyethane, and the like. Typically methyl isobutyl ketone is used. This solvent may be the same solvent used in the preparation of the hydrogen silsesquioxane resin.

  The reaction between the hydrogen silsesquioxane resin and the acid dissociable group precursor is typically performed for a time sufficient for substantially all of the hydrogen silsesquioxane resin to react with the acid dissociable group precursor. carry out. However, in order to increase the molecular weight of the silsesquioxane resin and / or improve the storage stability of the silsesquioxane resin, the reaction may be carried out for a long time while heating from 40 ° C. to the reflux temperature of the solvent (“ Thickening process "). This thickening step may be performed next to the reaction step or as part of the reaction step. Typically, the thickening step is performed for 30 minutes to 6 hours, preferably 1 to 3 hours.

The silsesquioxane resin having R ² SiO _3/2 units is prepared by reacting a hydrogen silsesquioxane resin (A) or a silsesquioxane resin (C) with a functional group precursor. Typically, a hydrogen silsesquioxane resin or silsesquioxane resin and a functional group precursor are obtained by catalytic hydrosilylation of the hydrogen silsesquioxane resin or silsesquioxane resin with the functional group precursor. Perform the reaction. The catalytic hydrosilylation reaction is carried out using the same or similar reaction conditions as described for the catalytic hydrosilylation reaction of the hydrogen silsesquioxane resin and acid dissociable group precursor described above.

As an example of the process, the hydrogen silsesquioxane resin (A) is reacted with a functional group precursor to prepare a resin represented by the following formula.
(HSiO _3/2 ) _m1 (R ² SiO _3/2 ) _m3 (HSi (OR ¹ ) O _2/2 ) _n (Si (OR ¹ ) _x O _{(4-x) / 2} ) _p
Wherein R ¹ , n, p, and x are as described above,
R ² represents a property-modifying functional group,
m3 is 0.01 to 0.25, typically 0.05 to 0.15,
m1 + m3≈m. )

Next, this resin is reacted with an acid-dissociable group precursor to prepare a resin represented by the following formula.
(HSiO _3/2 ) _m1 (RSiO _3/2 ) _m2 (R ² SiO _3/2 ) _m3 (HSi (OR ¹ ) O _2/2 ) _n (Si (OR ¹ ) _x O _{(4-x) / 2 P}
(Wherein R, R ¹ , R ² , n, p, m1, m2, m3, and x are as described above,
m1 + m2 + m3≈m. )

Alternatively, the silsesquioxane resin (C) is reacted with a functional group precursor to prepare a resin represented by the following formula.
(HSiO _3/2 ) _m1 (RSiO _3/2 ) _m2 (R ² SiO _3/2 ) _m3 (HSi (OR ¹ ) O _2/2 ) _n (Si (OR ¹ ) _x O _{(4-x) / 2 P}
(Wherein R, R ¹ , R ² , n, p, m1, m2, m3, and x are as described above,
m1 + m2 + m3≈m. )

Alternatively, the hydrogen silsesquioxane resin (A) may be reacted with a mixture containing a functional group precursor and an acid dissociable group precursor to prepare a resin represented by the following formula.
(HSiO _3/2 ) _m1 (RSiO _3/2 ) _m2 (R ² SiO _3/2 ) _m3 (HSi (OR ¹ ) O _2/2 ) _n (Si (OR ¹ ) _x O _{(4-x) / 2 P}
(Wherein R, R ¹ , R ² , n, p, m1, m2, m3, and x are as described above,
m1 + m2 + m3≈m. )

  In a typical method, a hydrogen silsesquioxane resin is reacted with an acid dissociable group precursor and a silsesquioxane resin is reacted with a functional group precursor.

  The weight average molecular weight of the novel functionalized hydrogen silsesquioxane-based resin of the present invention is about 500 to 100,000, preferably about 1,500 to 50,000, more preferably about 2,000 to 30,000. is there.

  The novel functionalized hydrogen silsesquioxane resin of the present invention has sufficient thermal stability, more specifically, an appropriate glass transition temperature (Tg), and photoresist processing (post application baking (PAB) and exposure). Preferred for post-bake (PEB)). The Tg of the functionalized hydrogen silsesquioxane resin of the present invention is preferably 50 to 250 ° C, more preferably 70 to 180 ° C, and most preferably 80 to 150 ° C.

Another embodiment of the present invention is the above-described (A) silsesquioxane resin and 7-diethylamino-4-methylcoumarin,
(B) one or more acid generators;
The provision of a photoresist composition containing This photoresist may be a negative photoresist or a positive photoresist, and may contain other components and additives. Typically, the silsesquioxane resin is present in the photoresist composition in an amount of 99.5% by weight or less, and the acid generator is 0.5 to 10% by weight based on the solid content in the composition. Present in the amount of.

  Said acid generator is a compound which generate | occur | produces an acid by irradiation of a radiation. This acid then dissociates the acid dissociable groups in the silsesquioxane resin. Acid generators are known and are described, for example, in EP 142928. Examples of the acid generator include, but are not limited to, onium salts, halogen-containing compounds, diazoketone compounds, sulfone compounds, and sulfonic acid ester compounds.

  Examples of onium salts include, but are not limited to, iodonium salts, sulfonium salts (including tetrahydrothiophenium salts), phosphonium salts, diazonium salts, and pyridinium salts.

  Examples of halogen-containing compounds include, but are not limited to, haloalkyl group-containing hydrocarbon compounds, haloalkyl group-containing heterocyclic compounds, and the like.

  Examples of diazoketone compounds include, but are not limited to, 1,3-diketo-2-diazo compounds, diazobenzoquinone compounds, diazonaphthoquinone compounds, and the like.

  Examples of the sulfone compound include, but are not limited to, β-ketosulfone, β-sulfonylsulfone, α-diazo compounds of these compounds, and the like.

  Examples of sulfonate compounds include, but are not limited to, alkyl sulfonates, alkyl imide sulfonates, haloalkyl sulfonates, aryl sulfonates, imino sulfonates, and the like.

  Preferred acid generators are sulfonated salts, particularly sulfonated salts with perfluoromethide anions.

  Other additives may be included in the photoresist composition. For example, when the photoresist is a positive photoresist, an organic base additive (or a quencher as an acid diffusion controller), a surfactant, a dissolution inhibitor, a crosslinking agent, and a sensitizer in the photoresist composition. , Antihalation agents, adhesion promoters, storage stabilizers, antifoaming agents, coating aids, and plasticizers may be included. Typically, the sum of all additives (not including the acid generator) is less than 20%, or less than 5%, based on solids in the photoresist composition.

  Typically, silsesquioxane-based compositions are handled in solution. The choice of solvent is governed by a number of factors such as the solubility and miscibility of the silsesquioxane resin and 7-diethylamino-4-methylcoumarin, or safety and environmental regulations. Typical solvents include ether containing compounds, ester containing compounds, hydroxy group containing compounds, and ketone containing compounds. Examples of the solvent include, but are not limited to, cyclopentanone, cyclohexanone, lactic acid ester (such as ethyl lactate), alkylene glycol alkyl ether ester (such as propylene glycol monomethyl ether acetate), alkylene glycol monoalkyl ester (such as methyl cellosolve), Examples include butyl acetate, 2-ethoxyethanol, and ethyl 3-ethoxypropionate. Typically, the solvent used for the silsesquioxane resin includes cyclopentanone (CP), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), Examples include ethyl 3-ethoxypropionate, methyl n-amyl ketone (MAK), and mixtures thereof.

  The amount of the solvent is typically 50 to 99.5% by mass, or 80 to 95% by weight based on the total amount of the silsesquioxane-based composition.

  The following examples illustrate the invention. As will be apparent to those skilled in the art, the techniques disclosed in the following examples show that the techniques found by the inventor work well in the practice of the invention, and therefore It is understood that this is an embodiment. However, those skilled in the art can make various changes to the disclosed specific embodiments in view of the disclosure of the present specification, and are similar or similar without departing from the spirit and scope of the present invention. You will recognize that results are obtained. All percentages are mass%.

[Example 1: Synthesis of hydrogen silsesquioxane resin (HSQ)]
100 g of toluenesulfonic acid monohydrate obtained by sulfonating toluene using concentrated sulfuric acid and anhydrous sulfuric acid vapor in a 500 mL flask equipped with a water-cooled condenser, thermometer, magnetic stirrer, and nitrogen bubbler ( TSAM) solution was added. Next, a solution obtained by adding trichlorosilane (10 g, 0.075 mol) to 50 g of toluene was dropped into the flask while vigorously stirring. After the addition, the mixed solution was washed with deionized water at least three times, and the organic phase was recovered. Next, the solvent was distilled off under reduced pressure using a rotary evaporator to obtain a hydrogen silsesquioxane resin solution having a solid content concentration of 5 to 25%.

[Example 2: HSQ and t-butyl (2-trifluoromethyl) acrylate resin]
About 0.1 mol of t-butyl (2-trifluoromethyl) acrylate (TBTFMA) and anhydrous toluene were mixed (50:50), and an olefin solution was prepared separately. About 200 ppm of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complex (platinum, concentrated) was added to this mixed solution.

The olefin solution was charged into a flask equipped with a water-cooled condenser, thermometer, magnetic stirrer, and nitrogen bubbler. After purging with nitrogen, the HSQ solution prepared in Example 1 (containing about 0.33 mol of HSQ solids) was gradually added to the olefin solution. After the addition, the mixture was refluxed for about 4 hours with gentle stirring. ^The hydrosilylation reaction was monitored by ¹ H NMR until the olefin peak disappeared completely.

  The solvent was replaced with a desired solvent (for example, propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl isobutyl ketone (MIBK)) to prepare a final resin solution having a solid content concentration of 4 to 45%. The molecular weight of the resin was 3,000 to 25,000.

Example 3: HSQ and bicyclo [2.2.1] hept-5-ene-2-t-butylcarboxylate resin
About 0.1 mol of bicyclo [2.2.1] hept-5-ene-2-t-butylcarboxylate and anhydrous toluene were mixed (50:50) to prepare an olefin solution separately. To this mixed solution, 200 ppm of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complex (platinum, concentrated) was added.

The olefin solution was charged into a flask equipped with a water-cooled condenser, thermometer, magnetic stirrer, and nitrogen bubbler. After purging with nitrogen, the HSQ solution prepared in Example 1 (containing about 0.33 mol of HSQ solids) was gradually added to the olefin solution. After the addition, the mixture was refluxed for 8 hours with gentle stirring. ^The hydrosilylation reaction was monitored by ¹ H NMR until the olefin peak disappeared completely.

  The solvent was replaced with a desired solvent (for example, propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl isobutyl ketone (MIBK)) to prepare a final resin solution having a solid content concentration of 4 to 45%.

[Example 4: HSQ and cis-5-norbornene-2,3-dicarboxyl anhydride resin]
About 0.10 mol of cis-5-norbornene-2,3-dicarboxyl anhydride and anhydrous toluene were mixed (50:50) to prepare an olefin solution separately. To this mixed solution, 200 ppm of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complex (platinum, concentrated) was added.

The olefin solution was charged into a flask equipped with a water-cooled condenser, thermometer, magnetic stirrer, and nitrogen bubbler. After purging with nitrogen, the HSQ solution prepared in Example 1 (containing about 0.33 mol of HSQ solids) was gradually added to the olefin solution. After the addition, the mixture was refluxed for 3 hours with gentle stirring. ^The hydrosilylation reaction was monitored by ¹ H NMR until the olefin peak disappeared completely.

  The solvent was replaced with a desired solvent (for example, propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), methyl isobutyl ketone (MIBK)) to prepare a final resin solution having a solid content concentration of 4 to 45%.

[Example 5: Preparation of SSQ resin containing 7-diethylamino-4-methylcoumarin]
The following components were mixed until uniform to prepare a photoresist composition.
Silsesquioxane resin prepared in Example 3 15 parts by mass Photoacid generator ((C ₆ H ₅ ) ₃ S ⁺ SbF ₆ ^- or (p- (CH ₃ ) ₃ CC ₆ H ₄ ) ₃ C ^- (SO ₂ CF ₃ ) ₃ , purchased from 3M Company) ... 0.3 parts by weight PGMEA (General Chemicals Electronic Grade) ... 84.7 parts by weight Furthermore, 0.01 parts by weight of organic base (7-diethylamino-4-methylcoumarin) was added to the above solution.

The prepared photoresist solution was filtered through a 0.2 μm syringe filter and spin coated onto a 6 inch silicon wafer. The coated wafer was baked at 130 ° C. for 60 seconds and irradiated with light having a wavelength of 248 nm or 193 nm at an exposure amount of 8 to 100 mJ / cm ² . The obtained film was further baked at 130 ° C. for 90 seconds and developed with 0.263N tetramethylammonium hydroxide (manufactured by Shipley, MF CD26). As a result, a high-resolution positive image with high contrast and reduced line edge roughness (LER) was obtained. In addition, the chemical stability of the prepared photoresist (that is, the storage stability of the resist) and the CD stability were remarkably improved.

Claims (3)

(I) a silsesquioxane resin having HSiO _3/2 units and RSiO _3/2 units, wherein R is an acid-dissociable group represented by the following formula:

(In the formula, each R ³ independently represents a linking group;
R ⁴ represents a second linking group,
L represents a linear or branched alkylene group having 1 to 10 carbon atoms, a fluoroalkylene group having 2 to 20 carbon atoms, a substituted and unsubstituted arylene group, a substituted and unsubstituted cycloalkylene group, and a substituted and non-substituted group. Represents a group selected from the group consisting of substituted alkali-lene groups;
R ⁵ represents a hydrogen atom, a linear or branched alkyl group, or a fluoroalkyl group,
R ⁶ represents an alkyl group or a fluoroalkyl group,
Z represents an acid dissociable group,
f is 0 or 1,
g is 0 or 1,
h is 0 or 1. )
(II) 7-diethylamino-4-methylcoumarin,
A composition containing The composition according to claim 1, wherein the silsesquioxane resin is represented by any one of the following formulas (i) to (viii).
(I) (HSiO _3/2 ) _a (RSiO _3/2 ) _b
(Wherein a is 0.4 to 0.9,
b is 0.1 to 0.6,
0.9 ≦ a + b ≦ 1.0. )
(Ii) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c
(In the formula , R ¹ represents a group selected from a hydrogen atom and a linear or branched C ₁ -C ₆ alkyl group;
a is 0.4 to 0.9,
b is 0.1 to 0.6,
c is 0.01 to 0.4,
0.9 ≦ a + b + c ≦ 1.0. )
(Iii) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d
(In the formula , R ¹ represents a group selected from a hydrogen atom and a linear or branched C ₁ -C ₆ alkyl group;
a is 0.4 to 0.9,
b is 0.1 to 0.6,
d is 0.05 to 0.45,
0.9 ≦ a + b + d ≦ 1.0,
x is 0-3. )
(Iv) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d
(In the formula , R ¹ represents a group selected from a hydrogen atom and a linear or branched C ₁ -C ₆ alkyl group;
a is 0.4 to 0.9,
b is 0.1 to 0.6,
c is 0.01 to 0.4,
d is 0.05 to 0.45,
0.9 ≦ a + b + c + d ≦ 1.0,
x is 0-3. )
(V) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (R ² SiO _3/2 ) _e
Wherein R ² is bicyclo [2.2.1] hept-5-ene-2-1,1,1-trifluoro-2-trifluoromethylpropan-2-ol, 2-trifluoromethylbicyclo [ 2.2.1] Hept-5-en-2-ol, 3,3,3-trifluoropropan-2-ol, and 2-trifluoromethyl-3,3-difluoro-bicyclo [2.2.1] A group selected from hept-5-en-2-ol ,
a is 0.4 to 0.9,
b is 0.1 to 0.6,
e is 0.01 to 0.25,
0.9 ≦ a + b + e ≦ 1.0. )
(Vi) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d (R ² SiO _3/2 ) _e
(In the formula , R ¹ represents a group selected from a hydrogen atom and a linear or branched C ₁ -C ₆ alkyl group;
R ² represents bicyclo [2.2.1] hept-5-ene-2-1,1,1-trifluoro-2-trifluoromethylpropan-2-ol, 2-trifluoromethylbicyclo [2.2. 1] Hept-5-en-2-ol, 3,3,3-trifluoropropan-2-ol, and 2-trifluoromethyl-3,3-difluoro-bicyclo [2.2.1] hept-5 -Represents a group selected from en-2-ol ,
a is 0.4 to 0.9,
b is 0.1 to 0.6,
d is 0.05 to 0.45,
e is 0.01 to 0.25,
0.9 ≦ a + b + d + e ≦ 1.0,
x is 0-3. )
(Vii) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d (R ² SiO _3/2 ) _e
(In the formula , R ¹ represents a group selected from a hydrogen atom and a linear or branched C ₁ -C ₆ alkyl group;
R ² represents bicyclo [2.2.1] hept-5-ene-2-1,1,1-trifluoro-2-trifluoromethylpropan-2-ol, 2-trifluoromethylbicyclo [2.2. 1] Hept-5-en-2-ol, 3,3,3-trifluoropropan-2-ol, and 2-trifluoromethyl-3,3-difluoro-bicyclo [2.2.1] hept-5 -Represents a group selected from en-2-ol ,
a is 0.4 to 0.9,
b is 0.1 to 0.6,
d is 0.05 to 0.45,
e is 0.01 to 0.25,
0.9 ≦ a + b + d + e ≦ 1.0,
x is 0-3. )
(Viii) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d (R ² SiO _3/2 ) _e
(In the formula , R ¹ represents a group selected from a hydrogen atom and a linear or branched C ₁ -C ₆ alkyl group;
R ² represents bicyclo [2.2.1] hept-5-ene-2-1,1,1-trifluoro-2-trifluoromethylpropan-2-ol, 2-trifluoromethylbicyclo [2.2. 1] Hept-5-en-2-ol, 3,3,3-trifluoropropan-2-ol, and 2-trifluoromethyl-3,3-difluoro-bicyclo [2.2.1] hept-5 -Represents a group selected from en-2-ol ,
a is 0.4 to 0.9,
b is 0.1 to 0.6,
c is 0.01 to 0.4,
d is 0.05 to 0.45,
e is 0.01 to 0.25,
0.9 ≦ a + b + c + d + e ≦ 1.0,
x is 0-3. ) The composition according to claim 2, wherein the silsesquioxane resin is represented by any one of the following formulas (i) to (iii).
(I) (HSiO _3/2 ) _a (RSiO _3/2 ) _b
Wherein R is isopropyl bicyclo [2.2.1] heptane-2-carboxylate, 2-methyladamantyl bicyclo [2.2.1] heptane-2-carboxylate, cyclohexyl bicyclo [2.2.1] Selected from heptane-2-carboxylate, 2-hydroxy-3-pyranyl bicyclo [2.2.1] heptane-2-carboxylate, and t-butyl bicyclo [2.2.1] heptane-2-carboxylate Group
a is 0.4 to 0.9,
b is 0.1 to 0.6,
0.9 ≦ a + b ≦ 1.0. )
(Ii) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (R ¹ OSiO _3/2 ) _c (SiO _4/2 ) _d
Wherein R is isopropyl bicyclo [2.2.1] heptane-2-carboxylate, 2-methyladamantyl bicyclo [2.2.1] heptane-2-carboxylate, cyclohexyl bicyclo [2.2.1] Selected from heptane-2-carboxylate, 2-hydroxy-3-pyranyl bicyclo [2.2.1] heptane-2-carboxylate, and t- butylbicyclo [2.2.1] heptane-2-carboxylate Group
R ¹ represents a hydrogen atom,
a is 0.5 to 0.7,
b is 0.2 to 0.45,
c is 0.05 to 0.2,
d is 0.01-0,
0.9 ≦ a + b + c + d ≦ 1.0. )
(Iii) (HSiO _3/2 ) _a (RSiO _3/2 ) _b (HSi (OR ¹ ) O _2/2 ) _c (Si (OR ¹ ) _x O _{(4-x) / 2} ) _d (R ² SiO _3/2 ) _e
Wherein R is isopropyl bicyclo [2.2.1] heptane-2-carboxylate, 2-methyladamantyl bicyclo [2.2.1] heptane-2-carboxylate, cyclohexyl bicyclo [2.2.1] Selected from heptane-2-carboxylate, 2-hydroxy-3-pyranyl bicyclo [2.2.1] heptane-2-carboxylate, and t- butylbicyclo [2.2.1] heptane-2-carboxylate Group
R ¹ represents a hydrogen atom,
R ² represents bicyclo [2.2.1] hept-5-ene-2-1,1,1-trifluoro-2-trifluoromethylpropan-2-ol, 2-trifluoromethylbicyclo [2.2. 1] Hept-5-en-2-ol, 3,3,3-trifluoropropan-2-ol, and 2-trifluoromethyl-3,3-difluoro-bicyclo [2.2.1] hept-5 -Represents a group selected from en-2-ol,
a is 0.4 to 0.6,
b is 0.2 to 0.45,
c is 0.05-0.20,
d is 0.01 to 0.15,
e is 0.01 to 0.25,
0.9 ≦ a + b + c + d + e ≦ 1.0,
x is 0-3. )